


A Boy and His Slut

by RiddleWraith



Series: Obito The Cum Slut (or Gratuitous Kaka/Obi Smut) [1]
Category: Naruto
Genre: Consensual Underage Sex, M/M, Masturbation, Sex, Underage Sex
Language: English
Status: Completed
Published: 2019-01-16
Updated: 2019-01-16
Packaged: 2019-10-11 04:28:55
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,293
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17439965
Author URL: https://archiveofourown.org/users/RiddleWraith/pseuds/RiddleWraith
Summary: More smut. Prequel to "Please, Master?". Obito's first time with Kakashi.





	A Boy and His Slut

**Author's Note:**

> More in the series. The prequel this time as I had been contemplating posting in my end note of "Please, Master?".

When Obito had hit puberty he had been intrigued by the thought of sex and he had stealthily obtained books to inform him of all the different types of sex. While normal male and female sex had sounded at the least fun, he was more intrigued by what males could do with one another sexually. Even aside from that, there was a whole world of masturbation opened up to him from all the books he had read. It wasn’t like he could easily find a partner anyway and he wanted to try fingering himself.

It sounded dirty but at the same time the descriptions in one of the books he’d gotten made it sound like he’d love the feeling. Once he had decided on his course of action he had stealthily obtained lubrication as well, knowing from the books that he would need it even for fingering himself. If he liked it and he wanted more, maybe he could work up the courage to get a toy. It’s not like anyone else had to know.

Henge was practically created to fool civilians into thinking you were someone of age, or at least someone other than who you were. It was just unfortunate for him that the day he’d obtained his lube he’d had to go on an overnight mission with his team. It wasn’t that he didn’t like them because he _loved_ his team but he didn’t exactly want to be caught sliding his fingers into his ass either. He’d _really_ wanted to try it that night but he supposed he’d have to wait.

It was too bad that he kept thinking about it throughout the day and getting more and more aroused. Luckily for him one of his acquired books had contained a low level genjutsu to hide the visible evidence of arousal and he had used it when briefly out of sight of his team to relieve his bladder. Well, it didn’t hide his steadily reddening cheeks in the least but it hid his erection at least. He caught Kakashi giving him odd looks from time to time during the day part of the mission but he ignored them.

He didn’t know what was up with the other boy lately. Weirdly enough, he had even been less of a bastard to Obito than usual. While Minato-sensei saw it as a sign that Kakashi was warming up to his team, Obito felt like it might be the coming of the apocalypse or at the very least just something really, really weird. Either way, he didn’t know if he wanted to know what was up with Kakashi.

He was fine with the other boy being less of a bastard as it meant he wasn’t jumping down Obito’s throat as much anymore. The day seemed to drag on with the weird events and Obito’s thoughts of masturbation and he finally decided as they set up tents for the night that he was going to try it out tonight. He had brought his lube with him anyway, trying to work up the courage to do it when he had the time. That being the case, when Kakashi was given first watch he cheered silently as that meant he would have the tent to himself for a few hours that night.

Despite his initial intentions when laying himself down on his bed roll he found himself drifting to sleep in spite of himself. He woke up a bit later to pitch black outside and he was disappointed. It looked like he would have to wait. He waited for Kakashi to come get him for his watch and after waiting for fifteen minutes with no sign of the other boy he decided he had time to do as he wanted.

That in mind, he quietly took his clothes off until he was bare, not wanting to get his mess on any of his clothes. Once that was done he dug in his pack for the bottle of lube and a small pack of tissues so he could clean up after himself. He shook with nerves as he lay back on top of the bedroll and squirted a small amount of lube on his hand, lubing up a few fingers and prodding experimentally at his hole. Finally, he slowly started to slide a finger into himself.

While the stretching feeling inside him was uncomfortable at first, he soon started to find it easier as his hole adjusted to his finger. When he felt no more discomfort he started to slide his finger in and out of himself, finding that he liked the feeling. He was quietly panting as he slid his finger in and out, slowly realizing that while it felt good, he now wanted _more_. With less trepidation than with the first finger he started to slide another into his hole alongside the first.

He waited for the discomfort to ease before he started his motions again. Once it did, he slid his fingers almost all the way out before sliding them back in, slowly picking up the pace of his hand until he was rapidly fingering himself, only just able to keep the noise down to rapid panting as he pleasured himself. It felt _so_ good that the books didn’t do it nearly enough justice. Because of his preoccupation he didn’t hear Kakashi until he walked into the tent and started speaking.

“Obito, it’s your… turn…” he trailed off, taking in the arousing sight of Obito naked and fingering himself. Obito’s head turned toward him abruptly and his hand stopped its motion, his fingers still inside himself as his eyes widened at the sight of his teammate at the entrance to the tent.

“K-Kakashi…” Obito said breathlessly, left so by the pleasure he’d been giving himself. What could he give as an excuse to this? His stoic at best teammate had just walked in on him finger fucking himself and his mind blanked on what to even do in this situation. He was startled when Kakashi abruptly zipped up the tent behind him and came toward him swiftly.

Before he could say anything Kakashi was removing his own clothes and leaning over him, his cock thick and erect.

“Let me take care of that for you, Obito.” He said, his voice rougher than usual as he gently took Obito’s hand and slid his fingers out of him. He watched numbly as Kakashi lubed his erection up and brought the head of it to his hole.

“Tell me, Obito. Would you like something bigger inside you?” he asked, his voice even rougher with lust. Obito nodded silently, turned on by the sight of his teammate’s arousal. Kakashi licked his pretty lips and Obito absently noted that this was the first time he’d seen Kakashi’s face without the mask over it.

Before he could think any more there was a pressure on his hole as Kakashi started to push the head of his cock into him. His hole gave way slowly, stretching bit by bit until the head was inside him. He panted, feeling more discomfort than a few fingers had caused him but not wanting this to stop. He felt every inch as Kakashi slowly slid his cock into him.

When he finally bottomed out they were both panting and Kakashi held himself still above him.

“Sorry for not… preparing you more.” Kakashi panted above him between breaths. “The sight of you… fingering yourself… just set me off. I needed to… be inside you.” He panted, making Obito’s hole pulse around him in arousal even as his cock visibly twitched.

“It feels uncomfortable… at the moment… but it doesn’t hurt.” Obito panted, amazed that something as big as Kakashi’s cock could fit inside him. Their breathing finally calmed as Obito’s discomfort slowly disappeared and Kakashi got used to the tight heat of Obito’s hole. They only had to wait a few minutes more for Obito’s discomfort to disappear completely. Once it did he merely felt full and he _loved_ the feeling.

“Kakashi, you can move if you want. I’m ready.” He said quietly, wanting to avoid alerting their other teammates of what they were doing. Kakashi wasted no time in pulling out to the head before slowly sliding back into him, setting a slow pace as they just enjoyed the slick drag of flesh against flesh together. Kakashi was enjoying the feeling of slowly pumping his cock in and out of Obito just as Obito was enjoying the sensation of slowly being filled and then emptied again.

Soon though, Obito wanted more. He had enjoyed the pace for awhile but now it just felt teasing. Kakashi wanted to move faster as well but figured it was better to go slowly for Obito’s first time so he didn’t hurt him. That changed though with Obito’s next words.

“Please, move faster.” He whispered urgently. “This feels good but it feels like you’re teasing me. I need more.” He pleaded quietly, making Kakashi’s arousal shoot through the roof. Once more, Kakashi didn’t waste a second and picked up the pace until he was rapidly filling and emptying Obito’s hot, slick hole with his cock.

“Sage Obito, you feel so fucking good around my cock.” Kakashi said hotly in his ear, fucking him quickly and loving the quiet sounds the other boy made in response to his pace.

“Please, please, please…” Obito begged quietly, not even knowing anymore what he was begging for. He just didn’t want this to ever stop. Kakashi picked up his pace yet more and increased the force of his thrusts, causing Obito to hold a hand over his own mouth as his moans started to get louder to try to muffle the sounds he was making. Sage, it felt _so_ good being fucked like this that he doubted he could ever settle for just a couple fingers inside him again.

“Fuck, Obito. You’re too perfect. I’m so fucking close. I want to fill your hot little hole with my cum and make you mine.” Kakashi panted hotly against his ear.

Sage, Obito wanted that. He wanted so badly to feel Kakashi fill him with his cum. He was getting close as well. Kakashi kept hitting something inside him that drove him closer and closer to climax. It was hard but he was able to quiet himself enough to speak without their teammates hearing him.

“Please Master, cum inside me. I need to be full of you.” Obito pleaded quietly. The force of Kakashi’s thrusts increased punishingly and within a few hard thrusts against that spot inside him he was cumming, tightening down around the thick cock inside him.

“Masterrrrrr!” Obito wailed, muffled enough behind the sudden presence of Kakashi’s hand over his mouth so that their teammates didn’t hear it and Kakashi did. Kakashi watched, still thrusting hard and fast into the rapidly tightening hole as Obito arched up and came, his cum shooting over his pale chest in ropes as his wide eyes took in nothing, too overwhelmed by the pleasure. The title alone was enough to make him cum so the sight of Obito coming undone on his cock only made it better. He was finally forced to stop thrusting as Obito tightened around him like a vice.

He came inside Obito’s hot, excruciatingly tight hole buried as deeply in the other boy as he could be. He groaned as he came in spurts, filling Obito with gob after gob of his cum and shuddering with his release. When he finally stopped cumming Obito was still tight enough to lock his cock in place and he had no problem with this. They both panted as they came down from their orgasms, muscles slowly loosening until Obito’s hole finally released his cock enough to slide it out of him.

Kakashi collapsed on the bedroll beside Obito and it was a minute or two before the two were breathing normally again. He wondered at the title Obito had called him by so he decided to ask.

“So, Master?” Kakashi asked curiously. Obito’s face immediately became hot with embarrassment.

“I… i-it was a spur of the moment thing. I wasn’t really thinking about it.” Obito said, his face beet red. Kakashi pulled him into a very thorough kiss, kissing him soundly before pulling away just a bit so Obito could see his expression.

“I love it. You should call me Master _every_ time I fuck you from now on.” Kakashi said seriously. Obito’s heart stuttered for a moment before beginning to beat more rapidly against his breast bone.

“E-every time?” he asked quietly.

“Yeah. I want to fuck you over and over and _over_ again. I don’t ever want to stop Obito. You fit around my cock so _perfectly_.” He said, grabbing Obito by the ass and pressing their groins together.

Obito whimpered at the sensation and the words, wanting nothing more than for Kakashi to fuck him every day multiple times a day for the rest of his life.

“I want to feed your hot, slutty little hole all the cum it can handle and then plug you so you’re always full of me. I want to pull out the plug the next time I fuck you and watch my cum drip from your perfect hole.” Kakashi said, circling a finger around Obito’s hole and pressing lightly against it but not pressing it in.

“Please…” he begged, wanting that so badly.

“Please what?” Kakashi asked roughly, pressing more insistently on his hole and slipping a finger into Obito, making him pant with both want and pleasure as Kakashi slowly and leisurely fingered him.

“Please use my slutty hole for your pleasure, Master. Please own me! Please fill me with your cum so _everyone_ knows whose cum slut I am!” He said, only barely keeping his voice down as he begged Kakashi. “I want everything you want to give me!” he moaned lowly, making Kakashi growl and flip Obito around so he was lying with his back against Kakashi’s chest.

Once Obito was on his other side he lifted Obito’s leg and wasted no time in sliding his renewed erection into Obito’s hot and still tight hole. He didn’t wait for Obito to adjust this time, fucking him as hard and fast as he could from that angle. When it wasn’t enough to satisfy Kakashi he sat up and instructed Obito to stay on his side, lifting Obito’s leg to his chest and telling him to hold it there. Obito did as he was told and Kakashi slid back into him, bracing his arms on the ground on either side of Obito as he pulled his cock out to the head.

Without warning he slammed his cock back into him. Obito barely muffled his cry with the hand not holding his leg, keeping his hand there as Kakashi kept up the brutal pace and force. All Obito could do was lay there and happily take what Kakashi gave him, muffling his loud cries of pleasure as Kakashi abused his hole for his own pleasure. Sage, he was _so_ glad Kakashi had walked in on him.

“You’re such a good little slut for me, Obito.” Kakashi growled lowly, not letting up on his pace in the least. “Once we get home I’m going to sound proof my apartment and fuck you so hard you can’t stop yourself from screaming. I want to hear all the hot little noises you make while taking my cock.” He said, knowing Obito was unable to respond through the cries he was muffling. Obito was _so_ fucking perfect and he didn’t know why he hadn’t seen it before.

He was practically _made_ to take cock and he was doing _so well_ taking Kakashi’s no matter how hard he gave it to him. He was the perfect little cum slut and soon Kakashi would have him trained so he did everything Kakashi wanted. He was already a natural at this part at least but he needed to learn Kakashi’s wants and needs before he would consider him trained. Obito needed to learn to anticipate when Kakashi just wanted to slide his cock into him and fuck him into oblivion no matter where they were.

He was bought out of his thoughts when Obito gave a full body shudder, his eyes widening as he came again. It was all Kakashi could do to keep moving as Obito tightened around him again. It wasn’t long before he was cumming again, groaning quietly as he filled his new slut up with yet more of his cum. He finally came to a stop, panting heavily as he carefully pulled free of Obito.

He collapsed next to Obito, both taking longer that they probably should have to recover. Still, it was a relatively short time before Obito finally had the presence of mind to get up and start dressing for his watch. Obito felt the slightest bit guilty that he hadn’t started his watch right away as he was supposed to but he couldn’t bring himself to regret what happened. Thankfully they were still in Fire Country territory so it was unlikely the enemy would have breached camp anyway.

Throughout the rest of his shift his mind kept going back to his encounter with Kakashi. The slow, viscous drip of fluid down his leg was hard to ignore as well and with every reminder of that was a reminder of being fucked so thoroughly he had temporarily lost the ability to even think. He had to calm himself before he was able to wake Rin to take the next watch. He was tense when he lay down beside Kakashi to go to sleep but despite that he fell asleep quickly.

The next morning they both treated it like it never happened for the most part but he now understood the looks Kakashi occasionally shot him. He hadn’t connected those looks with lust before because to be honest, it wasn’t something one would naturally connect with Kakashi. Regardless, they danced around one another for the rest of the mission and Obito was eager to get home to see if Kakashi would fulfill his promise. He knew that their sensei at least noticed they were acting a bit strangely but the man left it alone as they weren’t acting strangely enough to be suspicious.

It was thus a relief to see the gates of Konoha when they returned. It was the work of an hour to make their report and for them to be debriefed before they were allowed free time for the rest of the day. Kakashi shot off immediately for what Obito could only assume was his apartment and Obito felt more than a little excited. Rather than follow the other boy as he wanted to though, Obito went back to his own apartment for the time being.

It felt like only a short time later that there was a knock at his door and he opened it eagerly. Kakashi stood outside it and though he wore his mask once more Obito could still tell he was smirking. The other boy said nothing, instead grabbing Obito and leading him quickly to his apartment. Once they arrived Kakashi was quick to open the door and lead him inside.

Once inside, Kakashi closed and locked the door and Obito watched in awe as he activated a series of seals. He had no time to say anything as Kakashi swept up behind him, his arms circling around Obito and pulling him against himself.

“It’s time I fulfilled my promise.” Kakashi said hotly in his ear. He proceeded to do just that. Obito found himself screaming Kakashi’s name many times that day and the night following it. All in all, he was content.


End file.
